render elements - wrong transparency if light is in front of object

[klex167]

I try to render a transparent object with its render element (object select). If a rectangle light (invisible) is in front of this object the render element is wrong.
With deactivating the light the render element is correct.



My workaround for this case is to put an additional light right in front of the camera that overlaps the entire transparent object completely .. but this is not workling everywhere.

[shaio]

Hi klex167 ,

This result is to be expected when using Object Select with Transparent objects (I'll still double-check for issues of course). Please use the MultiMatte render element to create the alpha mask for transparent objects especially when you have lights and other self-illuminated objects on top. By using the MultiMatte render element you're creating the mask the same way as you used to do in V-Ray 3.

Take a look at the attached screenshot on how to do this. More info on for the MultiMatte render element and the object masks from V-Ray 3.7 and V-Ray 5 could be found in the following video.

[klex167]

Thank you Ivan! That will work.